---
title: "CVE-2017-11103\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2017-11103?format=md
keywords: index, follow
---

# CVE-2017-11103

Publication date 13 July 2017

Last updated 25 August 2025

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

## Cvss 3 Severity Score

**8.1 · High**

[Score breakdown](https://ubuntu.com/security/CVE-2017-11103?format=md#impact-score)

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## Description

Heimdal before 7.4 allows remote attackers to impersonate services with
Orpheus' Lyre attacks because it obtains service-principal names in a way
that violates the Kerberos 5 protocol specification. In
\_krb5\_extract\_ticket() the KDC-REP service name must be obtained from the
encrypted version stored in 'enc\_part' instead of the unencrypted version
stored in 'ticket'. Use of the unencrypted version provides an opportunity
for successful server impersonation and other attacks. NOTE: this CVE is
only for Heimdal and other products that embed Heimdal code; it does not
apply to other instances in which this part of the Kerberos 5 protocol
specification is violated.

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| heimdal | 17.04 zesty | Fixed 7.1.0+dfsg-9ubuntu1.1 |
| 16.10 yakkety | Fixed 1.7~git20150920+dfsg-4ubuntu1.16.10.1 |
| 16.04 LTS xenial | Fixed 1.7~git20150920+dfsg-4ubuntu1.16.04.1 |
| 14.04 LTS trusty | Fixed 1.6~git20131207+dfsg-1ubuntu1.2 |
| samba | 17.04 zesty | Fixed 2:4.5.8+dfsg-0ubuntu0.17.04.4 |
| 16.10 yakkety | Fixed 2:4.4.5+dfsg-2ubuntu5.8 |
| 16.04 LTS xenial | Fixed 2:4.3.11+dfsg-0ubuntu0.16.04.9 |
| 14.04 LTS trusty | Fixed 2:4.3.11+dfsg-0ubuntu0.14.04.10 |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)

## Severity score breakdown

CVSS version:
CVSS v3.0

**Base score**

8.1 · High

* Base metrics

  | Parameter | Value |
  | --- | --- |
  | Attack vector | Network |
  | Attack complexity | High |
  | Privileges required | None |
  | User interaction | None |
  | Scope | Unchanged |
  | Confidentiality impact | High |
  | Integrity impact | High |
  | Availability impact | High |
* Scores

  | Parameter | Value |
  | --- | --- |
  | Base score | 8.1 · High |
  | Exploitability score | - |
  | Impact score | - |

**Vector:** CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-11103)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2017-11103)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2017-11103)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2017-11103)

### Related Ubuntu Security Notices (USN)

+ [USN-3353-4](https://usn.ubuntu.com/USN-3353-4)
+ Samba vulnerability
+ 24 July 2017

+ [USN-3353-1](https://usn.ubuntu.com/USN-3353-1)
+ Heimdal vulnerability
+ 14 July 2017

+ [USN-3353-3](https://usn.ubuntu.com/USN-3353-3)
+ Heimdal vulnerability
+ 24 July 2017

+ [USN-3353-2](https://usn.ubuntu.com/USN-3353-2)
+ Samba vulnerability
+ 14 July 2017

### Other references

* <https://orpheus-lyre.info/>
* <https://github.com/heimdal/heimdal/commit/6dd3eb836bbb80a00ffced4ad57077a1cdf227ea>
* <https://www.samba.org/samba/security/CVE-2017-11103.html>
* <http://www.h5l.org/advisories.html?show=2017-07-11>
* <https://github.com/heimdal/heimdal/releases/tag/heimdal-7.4.0>
* <https://www.freebsd.org/security/advisories/FreeBSD-SA-17:05.heimdal.asc>
* <https://www.orpheus-lyre.info/>
* <https://www.cve.org/CVERecord?id=CVE-2017-11103>